Ministry of Education and Training
National Institute of Animal Science

Use of several agro-industrial by-products
in cattle finishing rations in Eakar district,
Daklak province
By Truong La
The first supervisor: Vu Van Noi, PhD.
The second supervisor: Trinh Xuan Cu, PhD.
A summarized thesis submitted in fulfillment for the Degree of Doctor of Philosophy in Agriculture
of the National Institute of Animal Sciences
Hanoi, August, 2010
Introduction
1. Rational
Agro-industrial by-product resources of Vietnam are abundant (47 million metric tons per
annum); however, utilization of agro-industrial by-products for animal feeding is limited.
According to Animal Production Department (2008) only around 18% of agro-industrial by-
products has been used as animal feeds. Because of feeds for cattle is in a shortage supply,
especially in dry reason, the performance of cattle is still far from their genetic potential.
Daklak province has a plentiful and diversified agro-industrial by-product resource, in this
province; Eakar district has a big source of agro-industrial by-products such as corn cob, corn stover
and cocoa pods. The utilization of these by-product as cattle feeds is necessary to overcome a feed
deficiency. If these by-products are included in finishing cattle with other locally available, cheap
feed ingredients, the economic efficiency of cattle production will be higher. For a sustainable cattle
production system, better utilization of agro-industrial by-products for feeding cattle is an
appropriate strategy. For the above reasons, this study: “Use of several agro-industrial by-products
in cattle finishing rations in Eakar district, Daklak province” was undertaken.
2. Objectives
The main objective of this study is to evaluate the potential of agro-industrial by-product
resources, which can be used for cattle feeding in Eakar district, Daklak province. The evaluation
will be based on the yield, chemical composition and nutritive values of agro-industry by products,

In Vietnam, in an attempt to increase meat production and quality and optimize genetic
potentials of cattle breeds, many studies on better utilization of locally available feed resources such
as rice straw, corn stover, molasses, cotton seed…as feeds for finishing cattle have been done so far
(Le Viet Ly, 1995). The results from the mentioned works have shown that with rations containing
locally available feed resources, cattle can have the ADG of 0.5 to 1.1kg/cattle/day). By using
locally available feed resources we can increase the performance of cattle, the economic efficiency
of cattle production and contribute to a friendly environment.
However, most of studies mentioned early focused on treated agro-industrial by-products. It
appeared that use of treated agro-industrial by-products as cattle feeds is only applicable for large scale
farms. For house hold farms, it is necessary to find another solution. For this reason, in our study,
supplementation of protein and energy feeds to the based rations of finishing cattle containing different
levels of agro-industrial by-products was chosen. In addition, a new source of industrial by-product:
cocoa pod was included in the based rations of finishing cattle.
Chapter 2: Materials and methods
2.1. Materials
Agro-industrial byproducts used in the experiments included three kinds: corn cobs, corn stover
and cocoa pods.
Two mature Lai Sind fistulated males were used for the in vitro gas production experiments
Sixty three Lai Sind males at 18-20 months of age were used for fattening experiments
2.2. Experiments of the study
The study included one survey and three experiments. They were:
2.2.1. Survey on the potential of agro-industrial by-product resource, which can be used for cattle
feeding in Eakar district, Daklak province.
2.2.2. Experiment N
o
1: Utilization of corn cob in finishing rations
2.2.3. Experiment N
o
2: Utilization of corn stover in finishing rations
2.2.4. Experiment N

agro-industrial by- products and other feeds
The chemical composition of agro-industrial by-products and other feeds as dry matter (DM),
crude protein (CP), crude fiber (CF), lipid, total ash (Ash), NDF and ADF were analyzed using the
above mentioned methods. ME (Metabolisable Energy) of agro-industrial by- products and other
feeds was estimated using DE (Digestible Energy) and TDN (Total Digestible Nutrients). The
equations for estimations as recommended by National Institute of Animal Sciences ( 2003) were :
ME (Kcal/kg CK) = 0,82 * DE
DE (Kcal/kg CK) = 0,04409 * TDN
The characteristics of by-product (corn cobs, corn stover and cocoa pods) digestion were
estimated using in vitro gas production technique recommended by Steingass of Menke (1988) The
amount of gas produced was recorded at different time of incubation: 3, 6, 12, 24, 48, 72 and 96
hours. A specialized software-NEWAY developed by Chen (1997) with the exponential equation of
Orskov and Mc. Donald (1979): P = a + b (1 - e
-ct
) was used to characterize the gas production from
agro-industrial by-products.
Where:
a = the gas produced from the readily fermented organic matter (OM) fraction (ml);
b = the gas produced from the slowly fermented OM fraction (ml),
c = the rate of fermentation of OM fraction (b);
t = incubation time (h)
P = gas produced at time't'
c. Estimation of the potential of agro-industrial by-product resource, which can be used for cattle
feeding in Eakar district, Daklak province
The output of protein and ME from agro-industrial by-products was estimated using the yield,
chemical composition and energy value of these by-products.
The estimation of how many percentage of DM and ME requirements for cattle in this district
can be covered by utilization of main agro-industrial by-products in the district was calculated on
the number of the tropical livestock unit in district per year (one unit for cattle = 250kg or 63kg
0.75

Ration 3-
treatment 3
(30% corncob)
- Molasses 40 40 40
- Cassava meal 24 14 4
- Corn cob 10 20 30
- Cotton seed 11 11 11
- Peanut cake 13 13 13
- Urea 1 1 1
- Mineral premix 1 1 1
Total 100 100 100
- Metabolisable Energy (MJ ME/kg DM) 9.8 9.5 9.2
- Crude protein (g/kg DM) 138.8 137.6 136.4
- Non-structural carbohydrate- NSC (%) 61.3 53.3 45.3
* NSC = 100 - (%NDF + %Pr + %Li + %Ash) (Stiffen et al., 1992; Stokes, 1991).
Rations and feeding
Three rations used in the experiment 1.1 were used in this experiment (Table 2.1). Feeds in
the form of TMR (Total mixed ration) were given individually to each animal at 8 am. and 4 pm.
every day. All animal had a free access to water.
Measurements
The average daily gain (ADG), feed conversion ratio (FCR), beef quality and economic
efficiency were estimated using measurements such as body weight change, feed intake, feed
cost, and slaughter data, which were recorded individually.
2.4.2.3. Experiment N
o
2: Utilization of corn stover in finishing rations
Experiment 2a: Effects of different levels of corn stover in rations on gas volume and
characteristics of in vitro gas production of diets
Three rations with three levels of corn stover: 5%; 15%; 25% were used to examine the effects
of different levels of corn cob in the rations on gas volume and characteristics of in vitro gas-

- Urea 11 11 11
- Mineral premix 1 1 1
Total 100 100 100
- Metabolizable energy (MJ ME/kg DM) 9.8 9.7 9.5
- Crude protein (g/kg DM) 132.2 136.3 138.7
- Non-structural carbohydrate- NSC (%) 67.4 58.6 50.5
Rations and feeding
Three rations used in the experiment 2.1 were used in this experiment (Table 2.1). Feed in the
form of TMR (Total mixed ration) was given individually to each animal at 8 am. and 4 pm. every
day. All animal had a free access to water.
Measurements
The average daily gain (ADG), feed conversion ratio (FCR), and economic efficiency were
estimated using measurements such as body weight change, feed intake, and feed cost , which
were recorded individually.
2.4.2.4. Experiment N
o
3: Utilization of cocoa pods in finishing rations
Experiment 3a: Effects of different levels of cocoa pods in rations on gas volume and
characteristics of in vitro gas production of diets.
Three rations with three levels of cocoa pods: 25%; 30%; 35% were used to examine the effects
of different levels of cocoa pods in the rations on gas volume and characteristics of in vitro gas-
production of the ration(Table 2.1). The gas volume and characteristics of in vitro gas-production of
each rations were estimated using in vitro gas production technique recommended by Steingass of
Menke (1988) (see: 2.4.2.1. b).
Experiment 3b : Effects of different levels of cocoa pods in the rations on performance of finishing
cattle and quality of beef.
Experimental animals
Fifteen Lai Sind young bulls aging of 18-20 months were used in this experiment. Deworming
all cattle was undertaken at the beginning of adaptation period of 14 days. During a 14-day
adaptation period, feeds were offered individually to the animals in exactly the same routine as was

Measurements
The average daily gain (ADG), feed conversion ratio (FCR), and economic efficiency were
estimated using measurements such as body weight change, feed intake, and feed cost , which
were recorded individually.
2.4.3. Statistical analysis
The following mathematical model of ANOVA was used to analyze the effects of different
levels of agro-industrial by-products in the rations on gas volume, characteristics of in vitro gas
production of diets, performance of finishing cattle and quality of beef:
Xijk = µ + αi + eik.
Where: Xik is the observed value of replicate k in treatment i
µ is the grand mean
αi is the fixed effect of treatment i
eik is the random error.
If ANOVA indicated a significant effect, then multiple t-tests were applied for comparison
of paired means. All statistical analysis were made using Excel and Minitab software, release
12.1 (1997).
Chapter 3: Result and discussion
3.1. The potential of agro-industrial by-product resource, which can be used for cattle
feeding in Eakar district, Daklak province
3.1.1. Cattle development situation and agro-industrial by- product output
3.1.1.1. Cattle development
Changes of cattle population in Eakar district from 2004 to 2006 are presented in Table 3.1
Table 3.1. The number of cattle through the year in Eakar district
Years Population (head) Growth rate (%)
As % of the province
population (%)
2004 22,111 - 15.8
2005 28,630 129.5 17.7
2006 28,036 98.0 12.7
Average 26,259 112.6 15.4

households
using by-
products
Percentage
(%)
Number of
households
processing
by-products
Percentage
(%)
Rice straw 30 13 43.3 3 23.1
Corn stover 40 12 30.0 2 16.7
Corn husk 40 6 15.0 2 33.3
Corn cob 40 4 10.0 0 0.0
Cotton seeds 20 4 20.0 0 0.0
Cocoa pods 20 1 5.0 0 0.0
Peanut leaves 20 7 35.0 0 0.0
Sugar cane
leaves
30 4 13.3 1 25.0
Molasses 30 22 73.3 0 0.0
Cassava waste 20 2 10.0 1 50.0
Average (%) 25.5 14.8
3.1.2. Agricultural by-product output in Eakar
3.1.2.1. Area, production of main cash crops in Eakar
Area and production of main cash crops in Eakar from 2004 to 2006 are presented in Table 3.3.
Table 3.3. Area (ha) and production (MT*) of main cash crops in Eakar from 2004 to 2006
Plant 2004 2005 2006 Average
Area Prod** Area Prod Area Prod Area Prod

By product to
main product
ratios
Rice 20 1.65 ± 0.11 1.81 ± 0.10 0.91 ± 0.08
Corn + Stover 20 4.65 ± 0.41 2.30 ± 0.38 2,02 ± 0,29
+ Cob 20 2.10 ± 0.34 7.70 ± 0.50 0.27 ± 0,05
Cocoa 20 1.94 ± 0.29 1.40 ± 0.24 1.38 ± 0.06
It was found out that: by-product to main product ratios of rice, corn, cocoa crops (rice to rice
straw, corn seed to corn stover, corn seed to corn cob and cocoa main product to cocoa pod) were
0.91; 2.02; 0.27 and 1.38, respectively. This by-product to main product ratio of rice straw in our
study was similar to work of Pham The Hue (2007) in Daklak (0.92). However, our figure was
slightly higher than that of Pham Kim Cuong et al., (2002) in Red river delta (0.89) and that
published by FAO (1994) (0.78).
3.1.2.3. Estimation of the potential of agro-industrial by-product resource, which can be used for
cattle feeding in Eakar district, Daklak province
Based on by product to main product ratios of crops in table 3.4, agro-industrial by-
products/year (MT) were calculated and are presented in table 3.5.
Table 3.5. Estimated agro-industrial by-products/year (MT) in the district
Crops
Main product in
the district
By-product in the
district
Total by-product
in province
As % of total by-
product in
province
Rice straw 36,352 33,080 280,156 11.8
Corn 73,862

them for feeding beef cattle, it is necessary to supplement rations with other ingredients, which are
rich in CP and non structural carbohydrate (NSC).
Nutritional value of several by-products
Nutritional value of some agro-industrial by- products is presented in table 3.7
Table 3.7. Nutritional value of some agro-industrial by- products
No By product TDN (%) ME (Kcal/kgDM)
1 Corn stover 42.89 1,551
2 Corn cob 46.08 1,666
3 Cocoa pods 44.30 1,602
Results showed that the total digestive nutrients (TDN) of three agricultural by-product were
relatively high from 42.89% to 46.08%. TDN of corn cob was the highest, followed by TDN of
cocoa pods. TDN of corn stover was the lowest. A similar trend was also observed in the
metabolisable energy (ME) content. The ME content of corn cob was the highest, followed by ME
of cocoa pods. The ME content of corn stover was the lowest.
The ME content of corn stover in our study (1,551 Kcal/kgDM), however, was lower than that
published by the National Institute of Animal Husbandry (2003) (1,711-1,962 kcal ME/kgDM).
3.1.3.2. Characteristics of in vitro gas production of some agro-industrial by- products
The cumulative in vitro gas production from some agro-industrial by- products is presented in
table 3.8.
Table 3.8. Cumulative in vitro gas production from some agro-industrial by- products
By-product Cumulative in vitro gas production at different time of incubation (ml/200mg DM)
3 h 6 h 12 h 24 h 48 h 72 h 96 h
Corn stover 2.36
a
4.57
a
9.03
a
22.64
a

37.00
b
40.72
b
SEM 0.82 1.11 1.13 1.65 1.83 2.22 1.88
Values bearing different superscripts a, b, c in columns differ significantly (P <0.05).
After 3 to 12 hour incubation, the cumulative in vitro gas production of corn stover and cocoa
pods was similar (P> 0.05) and higher than that of corn cob. After 24 hours of incubation, the
cumulative in vitro gas production from three agro-industrial by-products was different (P> 0.05).
The cumulative in vitro gas production from corn stover was the highest (22.64 ml), followed
by that from cocoa pods (18.39 ml). The cumulative in vitro gas production from corn cob was the
lowest (10.45 ml). After 96 hours of incubation, the cumulative gas volume from cocoa pods and
from corn cob was similar (P >0.05) and lower than that from corn stover (P <0.05).
It appeared that cocoa pods was fermented rapidly in the first phage and then they were
fermented slowly in the second and third phage of incubation.
The characteristics of in vitro gas production of the above agro-industrial by- products are
presented in table 3.9.
Table 3.9. Characteristics of in vitro gas production of three agro-industrial by- products
By product a (ml) b (ml) a + b (ml) c (%/h) Lag phase (h)
Corn stover 2.36
a
43.38
a
45.73
a
0.003 4.03
b
Corn cob 0.41
b
37.52

of cattle can be reared in the districts when using three agro-industrial by- products
Estimation of DM, CP and ME yields from three agro-industrial by- products
Based on total agro-industrial by-products/year, their chemical composition and nutritive
values, Dry matter, CP and ME yields from three agro-industrial by- products yields were estimated
and are presented in table 3.10.
Among three by-products, corn stover yielded the highest DM, CP and total ME, followed by
corn cob. Cocoa yielded the lowest DM, CP and total ME/year.
In total, every year, corn, cocoa crops can provide more than 150 thousand MT DM, 6 thousand
MT CP and around 240 million Mcal ME, if all of these by-products will be used for cattle feeding.
The number of cattle can be reared in the districts when using three agro-industrial by- products
Table 3.10. Dry matter, crude protein and metabolisable energy yields from three agro-industrial
by-products in the district
By-product
By-product
yield (fresh
basis) (MT)
Dry matter
(MT)
Crude Protein
(MT)
Total ME (Mcal
ME)
Corn stover 149,200 134,475 5,514 208,570,845
Corn cob 19,940 18,309 524 30,503,510
Cocoa pod 258 231 16 361,971
Total 169,398 153,015 6,050 239,444,066
Using the tropical livestock unit for cattle and their requirements for DM, CP and ME, the
number of cattle, which can be reared in the districts when using three agro-industrial by-products,
was calculated and is presented in table 3.11.
Table 3.11. The estimation of the number of cattle can be reared in the districts when using three

35.37
a
56.03
a
67.12
a
69.99
a
71.52
a
20% corn cob 6.22 14.57
a
35.16
a
51.48
b
61.19
b
64.89
b
66.63
b
30% corn cob 6.29 14.42
a
28.48
b
42.43
c
51.96
c

c
0.061 0.919
c
SEM 1.04 0.00 0.16
Values bearing different superscripts a, b, c in columns differ significantly (P <0.05).
As can bee seen from table 3.13, the potential gas production from the total degraded OM (a+b)
of rations containing different levels of corn cob was significantly different (P<0.05). The level of
corn cob in the rations had a negative effect on the potential gas production from the total degraded
OM (a + b) of rations. The higher the level of corn cob in the ration was, the lower the potential gas
production from the total degraded OM (a + b) of the ration was.
3.2.2. Effects of different levels of corn cob in the rations on performance of finishing cattle and
quality of beef. (Experiment 1b)
3.2.2.1. Live weight change of cattle
The live weight change of cattle fed on three rations differing in corn cob levels is presented in
table 3.14.
Table 3.14. Live weight change of cattle
Parameter
Ration 1
(10% corn cob)
Ration 2
(20% corn cob)
Ration 3
(30% corn cob)
SEM
Initial body weight (kg) 190.9 191.4 191.1 5.2
Final body weight(kg) 253.4 249.3 244.3 5.9
Average daily gain (kg/cattle/day) 0.745
a
0.689
b

SEM
DM intake (kg/head/day) 5.36 5.35 5.37 0.11
DM intake as % liveweight (%) 2.41 2.43 2.47 0.07
FCR (kg DM/kg gain) 7.21
c
7.77
b
8.51
a
0.39
Energy utilization efficiency (g
gain/MJ ME)
14.21
a
13.54
b
12.80
c
0.66
Values bearing different superscripts a, b, c in rows differ significantly (P<0.05).
Although ADG was different, DM intake (kg/head/day) and DM intake as % live weight of cattle
fed on three rations differing in the corn cob level was not significantly different. It indicated that
the palatability of the rations was similar. DM intake (kg/head/day) of cattle in our experiment, which
ranged from 5.35 to 5.37, was in agreement with Kearl (1982) and INRA (1989). According to Kearl (1982),
The DM intake requirement of cattle weighing 150-205 kg, gaining 0.5 kg/head/day was 4.2 - 6.2
kgDM/head/day. According to INRA (1989) DM intake requirement of cattle weighing 150-250 kg,
gaining 0.5 kg/head/day was 3.5 to 5.6 kg DM/head/day. However, DM intake (kgDM/head/day) of
cattle in our experiment was higher than that recommended by AFRC (1993) for the similar type of
cattle (3.7 to 4.9 kg DM/head/day).
Because different ADG and similar feed intake of cattle fed on three rations differing in the

45.0
b
0.76
Lean meat percentage (%) 39.9
a
38.5
ab
37.7
b
1.07
Values bearing different superscripts a, b, c in rows differ significantly (P <0.05).
The similar dressing and lean meat percentages of 46.3 to 48.6% and of 39.5 - 41.82% was also
found in the work by Nguyen Tuan Hung and Dang Vu Binh (2004) on Lai Sind cattle.
The pH of meat is an important parameter for assessing meat quality. pH of beef form cattle in
this experiment measured at different intervals after slaughtering is presented in Table 3.17.
Table 3.17. pH values of sir loin at different intervals after slaughtering
Time after slaughtering
Ration 1
(10% corn cob)
Ration 2
(20% corn cob)
Ration 3
(30% corn cob)
SEM
01 h 6.70 6.61 6.55 0.06
12 h 5.93 5.84 5.81 0.05
48 h 5.52 5.61 5.60 0.10
8 days 5.51 5.49 5.45 0.05
The pH values of sir loin of beef in this experiment tended to decrease from treatment 1 (ration
1) to treatment 3 (ration 3) as affected by the level of corn cob in the rations. However, the effects

composition of beef meat.
Table 3.19. Chemical composition of beef meat in the experiment (%)
Parameter
Ration 1
(10% corn cob)
Ration 2
(20% corn cob)
Ration 3
(30% corn cob)
SEM
Dry matter 26.06 26.56 26.91 0.58
Crude protein 21.21 20.70 20.45 1.15
Lipid 4.55 4.07 3.99 0.33
Total ash 1.39 1.41 1.32 0.15
3.2.2.4. Economic efficiency of beef fattening
The feed cost (Vietnam dong/kg feed) reduced from ration 1 to ration 3 (3,180VND;
2,990VND; 2,800VND) when the corn cob level in the rations increased from 10 to 30 %. The
reason was that the purchase cost of corn cob was cheaper than that of the other ingredients. This
explained why the level of corn cob increased, ADG decreased but the net profit
(VND/cattle/month) was similar. The net profit (VND/cattle/month) was 194,410VND;
190,893VND and 184,279VND for rations 1, 2 and 3, respectively.
3.3. Use corn stover in beef finishing rations
3.3.1. Effects of different levels of corn stover in the rations on gas volume and characteristics of
in vitro gas-production of rations (Experiment 2a)
The cumulative in vitro gas production from rations differing in percentage of corn stover is
presented in table 3.20.
Table 3.20. Cumulative in vitro gas production from rations differing in corn stover levels
Ration Cumulative in vitro gas production at different time of incubation
(ml/200mg DM)
3 h 6 h 12 h 24 h 48 h 72 h 96 h

11.95
b
23.35
b
37.29
b
48.33
b
51.59
b
53.40
b
SEM 0.72 1.23 1.82 1.59 1.38 2.36 2.75
Values bearing different superscripts a, b, c in columns differ significantly (P<0.05).
After 3 hour incubation, the cumulative in vitro gas production of rations differing in the
percentage of corn stover started to be different. However, the cumulative in vitro gas production of
rations containing 5 and 25% of corn stover was still similar. The similar trend was observed in the
cumulative in vitro gas production of rations after 6 hour incubation.
After 24 to 96 hours of in vitro incubation, however, only a significant difference in the
cumulative in vitro gas production was found between rations having 5 to 15% corn stover and the
ration having 25 % corn stover (P< 0.05). After 24 to 96 hours of in vitro incubation, the cumulative
in vitro gas production was similar for rations having 5 and 15% corn stover (P>0.05).
The cumulative in vitro gas production was the highest of the ration containing 5% corn stover,
followed by that of the ration containing 15% corn cob. The lowest cumulative in vitro gas
production was observed in the ration containing 25% corn cob.
It was concluded that the level of corn cob in the rations had a negative effect on in vitro gas
production of rations.
The characteristics of in vitro gas production of rations differing in corn stover levels are
presented in table 3.21.
Table 3.21. Characteristics of in vitro gas production of rations differing in corn stover levels

(5% corn stalks)
Ration 2
(15% corn stalks)
Ration 3
(25% corn stalks)
SEM
Initial body weight (kg) 192.1 191.8 193.1 5.5
Final body weight (kg) 254.1 253.5 248.4 4.1
ADG (kg/cattle/day) 0.738
a
0.735
a
0.658
b
0.042
Values bearing different superscripts a, b, c in rows differ significantly (P <0.05).
The ADG of cattle fed on rations containing 5 and 15% corn stover was significantly different
with ADG of cattle fed on the ration containing 25% corn stover (P<0.05). No difference in ADG
between cattle fed on the ration with 5% and 15 of corn cob was found (P>0.05).
ADG of finishing cattle decreased when the level of corn stover increased from 15 to 25 % in
the ration. The reasons was that corn stover is agricultural by-products with a high fiber content;
therefore the higher level of corn stover will increase the fiber content in ration. Consequently,
animals will use more energy for fermentation of fiber in the ration and then less energy will be
retained in the body of animals leading to a low ADG.
On the other hands, when the fiber content increases, the non-structural carbohydrate (NSC) of
the rations decreases. In this experiment, the calculated NSC level decreased from ration 1 to ration
2 and ration 3 (67.4%, 58.6%, 50.5%). NSC plays a very important role in feed digestibility, feed
intake and ADG of beef and dairy cattle. Bowman et al., (2004) showed that reduced NSC in the
ration of beef cattle led to a low dry matter and protein intakes and digestive protein.
It seemed that the ration with a higher potential gas production from the total degraded OM (a +

0.69
Values bearing different superscripts a, b, c in rows differ significantly (P <0.05).
Although the ADG of cattle fed on rations containing 5 and 15% corn stover was significantly
different with the ADG of cattle fed on the ration containing 25% corn stover, the DM intake
(kg/head/day) and DM intake as % live weight of cattle fed on three rations differing in the corn
stover level was not significantly different. The DM intake (kg/head/day) of cattle in our experiment,
which ranged from 5.39 to 5.51 kg/head/day, was in agreement with Kearl (1982). According to Kearl
(1982), DM intake requirement of cattle weighing 200 kg, gaining 0.5 to 0.75 kg/head/day was 5.2
to 5.4 kgDM/head/day.
The FCR (kg DM/kg gain) of cattle fed on rations containing 5 and 15% corn stover was
significantly different with the FCR of cattle fed on the ration containing 25% corn stover
(P<0.05). The FCR (kg DM/kg gain) of cattle fed on rations differing in corn stover levels, which
varied from 7.32 to 7.40, was in a range published by ARC (1980), INRA (1989) and AFRC
(1993) (7.1 to 8.8 kg DM/kg gain). The FCR (kg DM/kg gain) of cattle in our experiment was also
in agreement with work by Agricultural Diversification Project, in which the FCR of cattle in the
finishing phage averaged 8.2 DM/kg gain. However, the FCR (kg DM/kg gain) of cattle in our
experiment was lower than that published by Chi Cuong Vu et al., (2007). In their experiment,
when using of 27% corn stover in finishing rations, the FCR of cattle was 10.84 kg DM/kg gain.
In general, increased levels of corn stover in the finishing rations will lead to an increase in
FCR.
3.3.2.3. Economic efficiency of beef fattening
It was found that the difference (Vietnam dong/head) between output and input was the highest
for cattle fed on ration 1 (790,682 VND/head), followed by that for cattle fed on ration 2 (753,191
VND/head). The lowest difference (VND/head) between output and input (677,818 VND/head) was
found for cattle fed on ration 3. It was concluded that using 25% corn stover in finishing rations
lowered the economic efficiency of beef fattening.
3.4. Utilization of cocoa pod using in finishing rations.
3.4.1. Effects of different levels of cocoa pod in the rations on gas volume and characteristics of
in vitro gas production of rations (Experiment 3a)
The cumulative in vitro gas production from rations differing in cocoa pod levels is presented in

The characteristics of in vitro gas production of rations differing in cocoa pod levels are
presented in table 3.25.
Table 3.25. Characteristics of in vitro gas production of rations differing in cocoa pod levels
Ration a + b (ml) c (%/h) RSD
25% cocoa pod 68.97 0.075 3.076
30% cocoa pod 68.53 0.073 2.903
35% cocoa pod 68.27 0.070 3.462
SEM 1.56 0.002 0.197
As can bee seen from table 3.25, the potential gas production from the total degraded OM (a +
b) of rations containing 25, 30 and 35% cocoa pod was not different (P>0.05). No significant
difference in the potential gas production from the total degraded OM (a + b) of rations containing
25; 30 and 35% cocoa pod was observed (P>0.05).
It appeared that levels of cocoa pod ranging from 25 to 35% in the rations had no negative
effect on the potential gas production from the total degraded OM (a + b) of rations.
3.4.2. Effects of different levels of cocoa pod in the rations on performance of finishing cattle
and quality of beef. (Experiment 3b)
3.4.2.1. Live weight change of cattle
The live weight change of cattle fed on three rations differing in cocoa pod levels is presented
in table 3.26.
Table 3.26. Live weight change of cattle fed on three rations differing in cocoa pod levels
Ration 1
(25% cocoa pod)
Ration 2
(30% cocoa pod)
Ration 3
(35% cocoa pod)
SEM
Initial body weight (kg) 207.6 207.0 206.8 7.3
Final body weight(kg) 267.0 264.9 263.8 7.4
ADG (kg/cattle/day) 0.707 0.689 0.679 0.024

FCR (kg DM/kg gain) 7.60 7.88 8.15 0.34
Energy utilization efficiency (g
gain/MJ ME)
13.59 13.43 13.33 0.60